We are evaluating AD916X and AD917X for our application, here following are the requirements of our application
- To have an Instantaneous Baseband Bandwidth of 1200 MHz (centered at 0)
- Use DAC Sampling rate (FDAC) of about 8000 MSPS
- Use 2x or 4x interpolation in order to have easier onboard analogs, effective DAC Data rate (FDATA) will be 4000 MSPS or 2000 MSPS respectively
- DAC LO frequency needs to be around 2500 MHz
Following are our doubts
- As per AD916X and AD917X datasheets, using any Interpolator limits the Usable Bandwidth, suppose if we are interpolating by 4x, then Usable BW = 80% of FDATA/2 = 800 MHz. Is it correct? Is there any way to use it for 1200 MHz Bandwidth?
- In the case of AD916X, with FDAC = 8000 MSPS interpolation by 2x cannot be used as this will make the FDATA = 4000 MSPS, this FDATA is not supported for Complex data as per Note 2 under Table 35, is it correct?
- If we use 2x FIR85 in AD916X and send the 1200 MHz Bandwidth Baseband samples centered @ 0 Hz @ FDATA = 2000 MSPS, and if we mix it with a LO; then at the output of the DAC, LO to LO+600 MHz will contain (DC to +600MHz) baseband spectrum and its mirror image on LO-600MHz to LO, is it correct? An EZ gives a GIST on it: https://ez.analog.com/data_converters/high-speed_dacs/f/q-a/22481/ad9162-with-ads7-how-to-achieve-dc-to-6-ghz-in-2x-nrz-mode
- Do you suggest any DACs among AD916X, AD917X, or any other DACs to meet our requirements?